Dry-cleaning solvent



. With substantially pure dry cleaningsulvent such 4 as standardStoddard Solvent 1 have found that Patented July 20,. 1943 UNITED STATESPATENT OFFICE DRY-CLEANING SOLVENT Dwight L. Ebert, Chicago, 111.,assignor to non-is Products, Chicago, 111., a partnership composed ofPerry E. Norris and Dwight L. Ebert No Drawing. Application October 14,1940, Serial No; 361,109

1 Claim.

My invention relates to the art of dry cleaning and particularly to anovel method of treatin and water is then added to the solvent through ahumidifier or mixingdevice. The solvent after the absorbefacient isadded is stated to take up the water and form an optically clearsolution. It is the use of this latter solution which is stated toremove sweet spots and water soluble soil in silks and woolens which arenot ordinarily removed by immersion in dry solvent.

Solvent soluble dry cleaning soaps almost al ways contain moisture andit 'has often been claimed that the moisture in the soap goes intosolution in the soapy solvent and that the soap and moisture contenttogether have a cleaning action on water soluble spots.

No doubt the use of absorbefacients and soaps are effective incombination with various percentages of moisture in cleaning solvents'and their use assists in removing water soluble spots and stains. Ihave found however that soil in fabrics is ordinarily not either of thewater sol-' uble kind or the solvent soluble kind but combinations ofboth and that if solvent is activated by moisture so that a detergentaction is started then the cleaning action of the solvent continues. 5

I have further found that as long as moisture is present in cleaning'solvent in an optically clear solution that a tremendously greaterproportion of moisture is required to do effective cleaning work thanit: the solvent is activated' by moisture, particularly in removingwater soluble soil.

Absorbefacients andsoaps all tend to cause moisture to go into solutionin cleaning solvent,

by homogenizing the moisture in the solvent in a fine cloudymixturetha't evenvery low percentages of moisture such as -.1%, based onthe volume of the solvent, is effective in promoting an initialdetergent action or'the solvent-which when once started will continueuntil the soil is substantially completely removed and that this actionproceeds more eflec'tively without the Dresence of an absorbefacientordry cleaning soap,

though, if the dry cleaning soap is not of th solvent soluble kind, itseiiect is not ineffective.

To activate cleaning solvent I have found that moisture in the form ofcondensed dry steam may be effectively employed. As a specific exampleof one method of activating solvent, in a large dry cleaning plant Ihave found that by installing a steam separator on the steam line andintroducing dry steam into a pipe in the pump circuit with which solventin the washer is circulated that the solvent charge may be activated ina short period so that effective dry cleaning work can be done on silksand woolens soiled with so called water soluble soil.

The following specific directions will serve to teach a dry cleaner howto practice my inven-- tion.

Place a T in the pipe line leading into the washer. At the side openingof the T, place a reducing bushing to /2", then a close nipple, anordinary /2" steam valve, another nipple, a quick opening valve, then anipple to which a steam separator is attached. 'The steam separator, ofcourse, is hooked directly from the steam line, and a trap leading tothe return line. The steam circulates constantly through the separatorand any steam passing through the valves will be so called dry. Thepurpose of two valves i to insure against steam leaks into the solventwhen not wanted. This hook-up will be satisfactory for a 48 x 84 washer.of 175'gallons of solvent at the time when the steam is admitted. Theprocedure is as follows:'

The load is first cleared on the filter, then 'by means of lay-passing,the solvent is circulated by the filter through the pump and directlyback into the washer, and this apparatus is connected into the lineleadingfrom the pump to the washr. After the break, dry steam isinjected into the solvent for 15 seconds with both /2 valves wide open.During this time the washer is revolving. Then' after about 5 minutesthe valves, .are changed so that the solvent is again pumped through thefilter and allowed to clear up, after 5 which the load is finished.

A sample of the solvent after this 15 second injection contains from 9iof'1% moisture to of 1%. A sample-Lot the solvent after the injection.of the moisture appears cloudy and milky and will remain so for from 12to 24 hours.

The results obtained at a large dry cleaning plant in Chicago duringseveral weeks continuous operation have been remarkably satisfactory.The dry cleaner and spotters who are handling the men's clothes onwhichmost'ot the work has Such'a washer has a capacity a v as quickly aspossible.

' as to be visible only in been done state that they feel clean. liningsare brighter, and that their spotting and washing is much reduced. Thisplant, which is one 01 Chicagos largest and lowest in price is of courseinterested in getting good work as cheaply and It had been theirpractice to sort out the pass-ups and then spot what they could, andthen wash the bad ones. However,

- it before washing the bad ones they would,re -run them making whatthey would call an alky load. On this load they used alcohol, water, andsoap.

The so-called fancy silks, consisting of ones that are painted, someloosely dyed, etc., which could not be run with a regular silk loadwithout damage can be cleaned with my process, with much better cleaningand no bad results.

As one example of the use of my process the cleaner tool; a load ofdresses which were put aside for washing, and made. a steam run insteadof a strong soap run. This time he varied the procedure by giving thesolvent two injections oi steam about 10 minutes apart, the first onebeing 15 seconds, and the second 10 seconds. This load seemed to beexceptionally good.

Unless the steam is so called dry, small dropsolvent that the solventshould be moving in fairly large volume.

I have found that solvent activated with about .1% of moisture forms anexcellent hand spotter, for removing spots from light fabrics and felt,such as felt hats. In removing spots from garments with a dry solventthere is normally a tendency to form stain rings around the spot butwith my activated solvent such rings appear to be avoided.

While my activated solvent is particularly efiective for dry cleaning Ihave also found that hydrocarbon fuels can be activated with moisture ina similar manner and that such fuels tend to form less carbon ininternal combustion motors and the operation is quieter.

Having thus described my invention, what I claim as new and desire tosecure'by Letters Patent is:

A method of activating dry cleaning solvent of the class represented byStoddard solvent for eflective use in removing water soluble soil inlets of water will condense in the solvent so that p at all times it 'ispreferable to use dry steam which forms a sufliciently fine cloudyprecipitate the form of a cloud and not in visible drops. It seemsprobable that as the steam is being injected and condenses in the 'drycleaning which consists in distributing moisture by the injection ofsubstantially dry steam into the solvent in a percentage ofsubstantially .1% based on the volume of the solvent and in asufliciently finely divided condition as not to substantiallyprecipitate out on twelve hours standing.

